The proposed research is intended to provide information regarding early developmental changes in the perception of visual pattern structure by human infants. Information will be obtained concerning the usefulness of methodologies and stimulus materials that should provide important improvements over previous studies of early perceptual development. Moreover, preliminary empirical data will be collected regarding (1) the initial capacities for pattern organization and (2) changes that occur in the perception of pattern structure across the first four months. The experiments proposed deal explicitly with discrimination of higher-conditions and under conditions where lower-order sensory differences are ruled out. In addition, infants' ability to detect and use stimulus redundancy will be studied. The general methodology employs an operant sucking response for contingent visual stimulation and assessment of discrimination between novel and familiar patterns. The empirical findings will result in important information relevant to major theories of perceptual development and is intended to lead to later investigation and possible assessment of early developmental deficiencies in cognitive processes.